Abstract Plant genomes encode hundreds of receptor kinases and peptides, but the number known plant receptor-ligand pairs is limited. We report that Arabidopsis leucine-rich repeat kinase LRR-RK MALE DISCOVERER 1-INTERACTING RECEPTOR LIKE KINASE 2 (MIK2) for SERINE RICH ENDOGENOUS PEPTIDE (SCOOP) phytocytokines. MIK2 necessary sufficient immune responses triggered by multiple SCOOP suggesting t...